Switch SearchEngineTabHelper to use WebContentsUserData.

chrome/browser/ui/search_engines/search_engine_tab_helper.h

Index: chrome/browser/ui/search_engines/search_engine_tab_helper.h
diff --git a/chrome/browser/ui/search_engines/search_engine_tab_helper.h b/chrome/browser/ui/search_engines/search_engine_tab_helper.h
index 34896b6d617f9afa678d36877c239e58b2469036..ba68df26cef745576dbcb390dbe038893d0b58c2 100644
--- a/chrome/browser/ui/search_engines/search_engine_tab_helper.h
+++ b/chrome/browser/ui/search_engines/search_engine_tab_helper.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_UI_SEARCH_ENGINES_SEARCH_ENGINE_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_SEARCH_ENGINES_SEARCH_ENGINE_TAB_HELPER_H_
 
+#include "chrome/browser/tab_contents/web_contents_user_data.h"
 #include "chrome/browser/ui/find_bar/find_bar_controller.h"
 #include "chrome/browser/ui/find_bar/find_notification_details.h"
 #include "chrome/common/search_provider.h"
@@ -14,9 +15,10 @@ class SearchEngineTabHelperDelegate;
 
 // Per-tab search engine manager. Handles dealing search engine processing
 // functionality.
-class SearchEngineTabHelper : public content::WebContentsObserver {
+class SearchEngineTabHelper
+    : public content::WebContentsObserver,
+      public WebContentsUserData<SearchEngineTabHelper> {
  public:
-  explicit SearchEngineTabHelper(content::WebContents* web_contents);
   virtual ~SearchEngineTabHelper();
 
   SearchEngineTabHelperDelegate* delegate() const { return delegate_; }
@@ -29,6 +31,10 @@ class SearchEngineTabHelper : public content::WebContentsObserver {
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
  private:
+  explicit SearchEngineTabHelper(content::WebContents* web_contents);
+  static int kUserDataKey;
+  friend class WebContentsUserData<SearchEngineTabHelper>;
+
   // Handles when a page specifies an OSDD (OpenSearch Description Document).
   void OnPageHasOSDD(int32 page_id,
                      const GURL& doc_url,